Gramophone



Oct 18, 1932' I A. c. WiLLlAMs 1,883,841

GRAMOPHONE Filed April 20. 1929 INVE NTOR: Www/d yPatented Oct. 18, 1932 ALFRED CHARLES WILLIAMS, F DEAL, ENGLAND GRAMOPHON E Application led April 20, 1929, Serial No. 356,762, and in Great Britain January 21, 1929.

This invention relates to gramophones and refers more particularly to means for improving and regulating the sound from the sound box and tone arm.

According to the present invention I provide what may be called a soun-d chamber interposed between the tone arm and the horn or like member through which the sound is emitted. This chamber is formed with an aperture which is advantageously somewhat pear shaped and adapted to be more or less covered by a closing member in such a manner as to be able to regulate the volume of sound passing to the horn or like member.

The closing member may preferably consist of a slide held in guideways on or to one face of the said sound chamber and being fitted either within or externally thereof or alternately it may be pivoted to said sound chamber.

The closing member is adapted to be operated from outside the gramophone case similarly to the speed control means and may be connected by a cord or the like 0r by link movement to an appropriate knob or other iitting within easy reach of the operator for the easy control of the closing member. The cord, where used, may pass over suitable guide rollers provided for the purpose. A return spring is provided for returning the closing member to its initial position, i. e. entirely closing the aperture or leaving the latter entirely open as the case may be.

In order that the invention may be clearly understood I will describe the same with reference to the accompanying drawing which shows a gramophone device constructed according to the present invention.

Fig. 1 is a plan of a gramophone cabinet with the top plate partly broken away to show the device in position at the rear of the horn, and the operating mechanism. Fig. 2 is a front elevation to a larger scale of the' device, and Fig. 3 is a vertical section corresponding to Fig. 2.

A represents a gramophone cabinet, B the horn and C the connection to the tone arm. As will be seen the tone arm connects with a chamber D1 which is of appropriate size or partitioned suitably as at D2 and provided with an apertured wall E against the front or rear face of which can slide in reasonably close contact a shutter F provided with a pear-shaped or similar opening G2, such that by operating said shutter F by appropriate means, the volume of sound allowed to issue through the aperture G1 in the front wall E can be adjusted or varied to suit the record being played, in order to bring out the depth of tone and the bass notes distinctly and clearly.

The shutter F may move in slideways I-I and is operated by a cord I passing over suitable rollers or guides J to an operating lever K arranged near the table o1c the machine and held in position by suitable means such as notches L in a plate through which said lever K passes, there being also provided a spring or other appropriate means such as M to cause the shutter F to return to normal position when the lever K is released.

I claim:

l. In a gramophone in combination, a cabinet, a rectilinear sound box mounted therein, Said box communicating with the tone arm of the gramophone, said sound box having a circular aperture in one wall thereof, a shutter adapted to slide over said circular aperture, means for guiding said shutter, said shutter having a pear-shaped opening for controlling the volume of sound issuing from said circular aperture, and means for moving said shutter in either direction.

2. In a gramophone, in combination, a cabinet, a rectilinear .sound box mounted in said cabinet, one wall of said rectilinear sound box having a circular aperture therein, means for conveying sound to and from said rectilinear sound box, a shutter having a pear shaped opening for controlling the volume of sound leaving said rectilinear sound box, said pear shaped opening co-acting with said circular opening, slideways for said shutter on the inside of the apertured wall of said rectilinear sound box, means for moving' said shutter from its fully open position and a spring for returning it thereto.

ALFRED CHARLES WILLIAMS. 

